False positives when appends are conditional

[mholt]

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Even with simple=true, the linter reports about preallocating slices. Here is one such example:

var ents []*Entity // <--- ***false positive here***

if !m.fromMe() {
	e := entityWithID(m.normalizedCallerID)
	ents = append(ents, &e) // <-- conditional append only
}

for _, p := range m.participants {
	pID := p.normalizedID()
	if pID == senderID {
		continue
	}
	e := p.entity()
	ents = append(ents, &e) // <-- also conditional due to continue
}

As you can see, there is no way to know how many elements will be added to the slice - could be 0 or more, with no way to tell beforehand.

Loops that use continue, or appends which are conditional, should be omitted from this linter.

[kevgo]

Suggestion for a fix: Simply ignore loops that contain a continue statement. Avoiding false positives feels more important than having a few false negatives. ChatGPT can prototype the code to identify continue statements in the loop body's AST if needed.

[alexkohler]

Hi @kevgo, I unfortunately don't have the bandwidth to work on this issue, but that seems like a reasonable heuristic to me.